Tag Archives: ants

As an Entomologist, I’m absolutely fascinated by ants. Who wouldn’t be fascinated by these tiny insects that form amazingly complex and efficient societies that parallel those of humans?

Millions of Ants

We often think of ourselves as the most intelligent or civilized but I think ants can give us a run for our money! Their ability to cooperate with each other, to build nests, care for their young, exploit and manipulate resources of all kinds and defend themselves in many different ways have made them so successful that we often butt heads. We are struggling to keep the upper hand in agricultural and urban situations. They can be quite a nuisance, but one can’t help being intrigued!

Ants share the order Hymenoptera with bees and wasps, some of which also live in social groups. Ant colonies can range from a few dozen to millions of individuals, but unlike bees and wasps, there is no such thing as a solitary ant. Many form permanent nests while others are nomadic. Most are predators or scavengers, while some grow their own food. Some even farm and “milk” other insects like we do with cattle.

The Queen

Ant colonies typically consist of a queen (occasionally many), the only member of the colony to reproduce, and her sterile daughters or workers. Each year, new reproductive females and males, called drones, are produced. The winged males and females leave the colony to mate and start new colonies. The males die immediately after mating and the females shed their wings and become queens of their own colonies. Some colonies do not even have queens, only reproductive workers called gamergates. Some ant queens can live for up to 30 years, placing them high among the longest lived insects.

If the queen is the heart of the colony, the workers are the blood. She produces them, they develop into adults and they take care of every aspect of the colony. Their responsibilities range from tending to the queen, the young, the nest and each other, to foraging for food or building materials and protecting the nest. The younger ants can be founding tending to the inner workings of the nest while the older ones, who are more expendable, have the more hazardous task of foraging.

Worker Ants

Workers can be different sizes, but the largest are the soldiers (remember, all are female!). Soldiers are strong, brave, and often have sizable mandibles! Any worker ant will sacrifice itself for the good of the colony. Who do you think invented suicide missions? This selfless devotion and ability to work together as one unified organism is what has made them so successful. There are so many ants that they make up an estimated 20% of the terrestrial biomass on earth. That number far surpasses that of vertebrates!

We have several types of ants here at the Cockrell Butterfly Center, some captive, and some, well, not so captive. A facility such as ours is a haven for pest species including cockroaches, fruit flies, and lots and lots of ants. We’ve always had ants in the conservatory. The conditions are favorable and the food, including fallen butterflies, is plentiful. In the conservatory, they are manageable and they don’t really bother anyone.

photo credit: emills1
Can you see the queen leafcutter ant?
She’s so much bigger than the rest!

Of over 12,000 described species of ants, only about 20 species are considered “pests” – i.e., they mess with humans or our possessions in some way. The pest species are mostly very small ants including sugar ants, ghost ants, pavement ants, and others, that sometimes get into our houses and larders. Unfortunately one of our uninvited residents is perhaps the hardest species of household pest ants to control, crazy ants.

Crazy ants, also known as longhorn crazy ants (Paratrechina longichornis) have earned their common name from their erratic and “crazy” movements. They move extremely quickly and in all different directions. They do not form foraging trails like most other ants, instead, they will go straight towards a food source, then meander all over the place back to their nest, making their actual nest very difficult to find!

Crazy ants feed on a wide variety of things including live or dead insects, fruits, nectar, honeydew (a secretion from hemipteran insects), and many household foods. The best way to control these ants is exclusion, or keeping them out and keeping food and water sources out of the area.

Crazy ants are very easily identified. They are small, dark colored ants with very long antennae. They are monomorphic, meaning all of the workers look the same and are the same size. They do not sting but they can be present in such great numbers that they can be quite a nuisance. We’re currently doing everything we can to combat them!

New Leaf Cutter Ant Colonies!

Luckily, there are also ants that we are glad to have. After losing our tropical leaf cutter ant colonies in 2010, we have been blessed with 3 new colonies of Texas Leaf cutter ants (Atta texana).

I bet you didn’t know that leaf cutter ants are native to Texas! Leaf cutter ants are very fascinating and fun to watch! The workers use their powerful jaws to cut pieces of about 200 different types of leaves. They do not eat the leaves but carry them back to the nest. Once there, they chew them into a mulch that they use to grow a special type of fungus. The fungus is what the ant larvae feed on, so they are true fungus farmers!

Leaf cutter workers are polymorphic, meaning the workers differ in size and appearance. The smallest workers, called minims, are meant to tend to the fungus garden, queen, and brood. The minor workers, which are a bit bigger, patrol the nest and are the first line of defense. Mediae are larger workers with strong mandibles that forage, cut leaves and bring them back to the nest. The largest are the major workers. They act as the soldiers and are often very large with big strong mandibles that can break the skin. I know this from experience!

Leaf cutter ants also do not posses a stinger, but they sure do bite and will not let go! The mutualistic relationship between the ants and the fungus is quite incredible. The fungus must be actively maintained and cultivated by the ants. It constantly needs new fresh leaves to grow and survive. The ant larvae feed exclusively on the fungus and need it in order for them and the colony to survive. The ants constantly monitor the fungus to see if any leaves are toxic or if any other competing fungus is growing. They will destroy any other fungi with a bacterium that grows on their skin and secretes antimicrobial chemicals. WOW!

Two of our new colonies came from the University of Texas, which was so generous to donate them to us! When we got them I noticed that the fungus gardens, which are usually green, were all white. These ants had been fed on oats instead of leaves, which they can apparently manipulate in the same manner. It’s really cool, they look like some formations you would find in a cave. One of these colonies will soon be on display for everyone to watch as they busily carry leaf fragments to their gardens.

There are so many interesting things about ants. They really are diverse and fascinating. I encourage you to read up on them a little bit; even just by clicking the links in this blog, you may find out things you would have never expected!

Next time you see ants trailing in your house or outdoors, don’t think of them as just a nuisance, think of how incredible they are and how hard they work. You may have a newfound respect for the little critters.

Ants are endlessly fascinating. They seem so HUMAN in the way they bustle around, cooperating in all things whether building great metropolises, hauling food, overcoming enemies or taking care of their queen and their baby sisters. They epitomize industry and selfless devotion to the cause – their colony. Of course as children we may have squished dozens of these little workers, but we have also watched their activities in wonder, marveling to see so many of our own behaviors reflected in their activities.

With 12,000 species world-wide, ants are the most diverse and widespread of the social insects, which include termites and some wasps and bees. Ants are found on every continent and in every habitat, but are especially successful in the tropics. Everywhere they are abundant and in many habitats are the dominant organisms, in terms of individuals far outnumbering all other animals. They have few enemies and many have long-lasting, stable colonies. Individual ants are remarkably long-lived, as insects go, with queens living as long as 13 to 15 years or so, and some workers surviving 4-7 years. Unlike other social insects such as termites or honeybees, which are quite specialized, ants have many different ways of life. Some have mutually beneficial relationships with plants or other insects. Although a few ants are household pests, and some may cause agricultural or other damage, many are beneficial in terms of controlling pest populations, cleaning up wastes, and aerating the soil.

All ants are social; there are no solitary species. Some are tiny, less than 1/16 of an inch long, while some tropical species are over an inch in length. Depending on the species, ant colonies may be made up of only a few individuals, while others number in the millions. In this and other ways, ant societies appear to parallel human societies. Some are simple hunter-gatherers, with little specialization among workers, while others have huge and sophisticated societies with highly specialized tasks divided among different “castes.” Driver ants in Africa and army ants in South America are ruthless predators, moving in huge numbers from temporary bivouac to bivouac in search of prey. Any of us who read “Leinigin versus the ants” when we were in school can still remember the terror inspired by the image of a huge river of driver ants overrunning everything in its path. Leafcutter ants also have huge colonies, but theirs are sedentary and underground, sometimes lasting more than 20 years. Leafcutters are farmers, chewing up fresh leaves and fertilizing them with their saliva and feces to provide a rich substrate for the fungus they cultivate as food for the colony. Harvester ants in dry grasslands stockpile seeds in underground storage areas. Other ants are ranchers, herding and protecting groups of tiny, honey-dew producing insects such as scale and aphids. Desert-dwelling honeypot ants use their own sisters as “cisterns” to store honeydew. Formica ants in boreal forests make huge mounds of pine and spruce needles, which serve to regulate temperature and humidity. Some ants do no work themselves, instead robbing pupae from neighboring ant nests, and then forcing the captured ants to work as slaves.

Dr. Mark Moffett
Photo by Frank J. Sulloway

Mark Moffett, renowned National Geographic photographer and explorer, has made a career out of his fascination with ants, and will be at the museum to talk about his favorite organisms on Wednesday, September 15. An enthusiastic speaker with – needless to say – wonderful photographs – Mark will regale his audience with tales of warfare, industry, and cooperation. He encourages all ages to attend!

Last week we got an interesting photo from a man named Alex in Guanajuato, Mexico. At first glance it looks like a stem with green thorns and some really weird, spiky, alien-looking bugs. The “green thorns” are actually insects that often get dismissed as, well, green thorns! These little guys are called treehoppers and they are everywhere, constantly being overlooked because of their excellent camouflage. They belong to the order Homoptera, which is notorious for containing almost all of the worst plant pests, including everyone’s favorite, the aphid! This order also includes interesting, non-pest insects like the cicada and the masters of disguise, treehoppers and leafhoppers. Most entomologists today lump the order Homoptera with Hemiptera, or true bugs such as stink bugs, leaf-footed bugs, and assassin bugs. I, however, think they’re different enough to have their own group.

So, as I said, most treehoppers are not considered pests except for a small handful, including this little guy, the Keeled Treehopper (Antiathe expansa). They are known to attack plants in the family Solanaceae – especially tomatoes, eggplants and chile peppers. Alex found these guys all over his chile plant! In large enough numbers, they can seriously injure and even kill these plants. The problem is that, unlike more efficient insects like butterflies, beetles and flies, the young nymphs and adults eat the exact same thing. They use a sharp beak to penetrate the tissues of plants and suck the sap. All homopterans feed this way and that’s why so many of them cause damage to plants. All of this sap eating causes these insects to excrete a sugary liquid called honeydew which ants go crazy for! The ants will “milk” the honeydew from the homopteran and in return for the yummy snack, protect them from other predators. For example, ants who farm aphids for honeydew will keep the hungry ladybugs at bay to protect their precious nectar. For this reason, ants are very often associated with homopterans.

So, what are the little spiky, weird orange guys? You guessed it, the nymphs! Very often, treehopper nymphs will look very different from the adults, but as time goes by, with every molt, they will lose their spines and start to resemble the green thorn-like adults. Treehoppers come in a wide array of fascinating and even downright bizarre shapes and appearances. Those found in the tropics are a bit larger and sport vibrant colors and odd protuberances unlike any other insects. Next time you are out and about, look a little more closely, and you’re sure to spot them!

Remember, if you find an odd looking bug and would like to know what it is, snap a picture and send it to us at blogadmin@hmns.org. Happy bug watching!

For this blog, I thought I would share with you and answer some of the most common questions we get here in the Cockrell Butterfly Center, specifically related to butterflies. The question that we get asked the most, by far, is:

“How long do the butterflies live?”
Well, typically they live in our center for about two weeks, but there are a few exceptions. The longwing butterflies, in the genus Heliconius, can live for months. They not only feed on nectar, but also pollen. They extract very nutritious amino acids from the pollen, which allows them to live longer. Another butterfly that seems to live a long time is the rice paper, Idea leuconoe.

“How many butterflies do you have in here?”There are anywhere from 1,500 to 2,000 butterflies flying through the Butterfly Center at a time. On really, bright sunshine-y days when the butterflies are very happy it seems like there are way more than 2,000 and on gloomy cloudy days the butterflies hide and it seems like there are fewer than 1,500.

“What is that liquid in the red bowls?”
That is our butterfly feed. We cannot always guarantee fresh nectar from blooming flowers to the butterflies, so we supplement them with this instead. It is a mixture of 4 parts water to 1 part sugar with a cap full of amino fuel. Many people ask me if they can make a similar set up to put in their yard. Absolutely! But, do be prepared for ants and bees to take advantage of the nectar as well as the butterflies.

“Why do you have fruit and nectar for the butterflies?”
Some butterflies are nectar feeders and others are not. Most of the butterflies that do not drink nectar are fruit feeders. We like to give our butterflies a variety of tropical fruits, including kiwi, papaya, mango, cantalope and honeydew. They especially love super ripe black bananas and on occasion they get starfruit, which we pick from our tree in the butterfly center.

Some male butterflies, especially swallowtails and sulphurs, will do what we call “puddling.” They are attracted to salts and amino acids in mud and will actually drink from it, sometimes in very large numbers called a “puddle club.” It is thought that the males benefit from the salts, increasing their reproductive success – but of course it is not known for sure and scientist are still trying to work out the reason.

Some butterflies are also attracted to tree sap, carrion, and dung. Sometimes our iguana, Stretch, will leave some excrement behind and – low and behold – a butterfly will land on it and start drinking. We have even thought about collecting some iguana poop and putting it in a huge pile for the butterflies – but we eventually decided against that.

“Do the butterflies breed in here?”
The butterflies are free to mate but due to USDA regulations we are not allowed to provide them with host plants. Female butterflies will only lay eggs on a specific plant that her caterpillars can eat, so we have to make sure that no host plants are in the butterfly center. This involved alot of work when we first opened because we have so many species of butterflies and they do not all feed on the same plant.

The reasoning behind this policy is that the USDA believes that the escape potential of a caterpillar is greater than that of an adult butterfly; if the butterflies were allowed to lay eggs, then there would be caterpillars everywhere, and the chance of someone leaving with one on them would be pretty high.

Another obvious reason that we do not want caterpillars is that they would eat all our beautiful plants. Now, just because we do not want caterpillars in the butterfly center doesn’t mean we do not like them. Caterpillars are so much fun to have in your garden. If you plant the correct host plant, you can attract native butterflies to your yard. You can find a list of host plants that you can plant in Houston by clicking here.

“Why won’t that butterfly leave the other one alone?”
The butterflies in this video represent this question (It’s not the best quality, so sorry!). These butterflies are courting. Although they look like different butterflies, they are subspecies of the same species, Heliconius erato. The male is flying above the female trying to entice her to be his girlfriend with his wonderful smell. Sometimes the female is so attractive that two or three males will be courting her. This behavior can almost always be viewed in the butterfly center – you just have to look for it.

Another courting behavior that is encountered a lot is two butterflies chasing each other. They will flutter around each other in circles, resembling a graceful rehearsed dance. This normally happens in a nice sunny area, so look for it next time you are here.

Well, I hope you enjoyed my question/answer session. If you have any questions please feel free to ask in the comments and I will be happy to answer!